Security devices, such as for example, padlocks and other types of conventional locks are known in the art. Many security devices are provided for restricting access to equipment and control instruments, including, for example, electrical components, such as switches, dials and push buttons, and fluid system components, such as valves and pressure regulators. One exemplary security device is a valve lockout device to prevent the operation of a valve, which may be utilized during maintenance of the associated fluid system or under other conditions in which the flow setting of the valve must not be changed.
Valve lockout devices typically restrict movement of the handle attached to a valve stem configured to actuate the valve. These devices generally use a feature to stop, resist, push, or pull against the body of the valve or the conduit attached directly to the valve. Due to the large number of valve manufacturers and the wide variety of valve sizes, conduit sizes, valve body shapes and valve handle dimensions, the types of valves with which a single such device design may be used is limited, requiring retention of several types or sizes of handle restricting valve lockout devices to accommodate the many types and sizes of valves in service at a typical plant. In addition, the installed position and location of the valve itself can vary. The orientation of the valve (vertical or horizontal) and the clearance of the valve from a wall, piping, or other pieces of equipment may affect the ability of a lockout device to be assembled with a valve. Moreover, in certain designs, if a lever style handle is attached to a valve and the valve is locked out in any other position except open, the handle extends beyond the envelope of the valve body. In this condition, the handle becomes a moment arm that may be dislodged with sufficient force, compromising the locked out state of the valve.